Problems with WRT54G...

Since installing this router two months ago, every 18 to 24 hours the router and modem must be restarted after loosing my internet connection, I could still ping the router, but nothing on the internet. A new router is 7 days old, with latest fireware. I have been told that there is a IP address conflict with this modem and router. Because of that I have changed my IP address on the router to 10.10.10.1.
Has anyone else had problems with this combination of modem and router or, ISP? Is this normal, to restart a router every day or two? Any suggestions are needed!
Thank you.